Biologists Amplify Dialogue on Genetically Engineered Crops With a Symposium on Ecological Implications
Cockrell, Public Affairs
More than 20 biological scientists from the United States, Canada, Europe and Latin America converged at Berkeley late last week to share their diverse scholarship on the hotly debated issue of genetically modified food crops.
Transgenic crops raise a wealth of issues -- among them health and environmental risks, ethics, agronomic effectiveness, intellectual property rights and corporate control of food production. But the March 2-4 symposium focused solely on the ecological implications of this emerging technology -- an aspect that often gets short shrift, say organizers of the symposium.
"The pro-biotechnology people say that sound science should prevail in the production and regulation of genetically modified food," said Miguel Altieri, associate professor of environmental science, policy and management. "But sound science has many dimensions, and at our workshop, one such dimension -- ecological research -- raises important concerns about the safety of this technology. It's important to bring all sides of the scientific inquiry to the table."
Altieri and the Oakland-based think tank Institute for Food and Development Policy (Food First) hosted the gathering of scientists who take a cautionary approach to transgenic technology. They included entomologists, soil specialists, ecologists and agronomic policy advisers, from far-flung institutions, involved in research on the delicate balance of natural processes potentially affected by genetic modification of crops.
Biotechnology develops new crops through insertion of foreign genetic material (for example inserting genes from bacteria or fish into a food crop) -- a process that does not occur in nature. "As a result," said Altieri, "we can create new life forms that we have no evolutionary experience with, and which could not be created by conventional breeding."
Although genetically modified crops have been rejected by much of the European public and banned by a number of governments there, they have made considerable headway in the United States. Seventy-five percent of the world's genetically-modified crops are grown in this country, including 80 million acres of corn whose genetic structure has been artificially modified by adding genes from bacteria, in the hope of making it more resistant to chronic pests like the European corn borer.
"One third of the corn sold in the U.S. is Bt corn," University of Minnesota Professor David Andow told more than 150 students, faculty and researchers at a Thursday afternoon seminar showcasing ecological issues raised at the symposium. "It's the largest scale pest control experiment in world history."
Fields planted with genetically modified, or Bt, corn seem to produce higher yields for farmers during the corn borer's most aggressive years, the entomologist said. But he's worried about what may happen when the pest, through mutation, develops resistance to Bt corn, much as insects have done repeatedly in response to chemical pesticides.
"Entomologists say insects developing resistance is a question of when, not if," Andow said. In the worst-case scenario, the corn borer could develop resistance to Bt corn within 4 to 6 years, he said, and in the best case, more than 20.
Before resistant insect strains develop, said Andow, "There's a huge list of things we need to think through, to design well thought out resistance management systems." The fact that millions of acres of U.S. cropland is already planted with genetically modified corn makes the problem more difficult, and urgent, than if research and sound management policy had come first, he said.
Another scientist, Allison Snow of Ohio State University, summarized research indicating that transgenes introduced to make crops more resistant to insects, diseases, herbicides or stress may be migrating to nearby invasive weeds through gene flow and crop-weed hybridization. The fear is that the weeds, too, may become more hardy, and their population could explode.
The wild sunflower is one example of a troublesome weed. "It's not something you want to become more common, even though they're pretty to look at. We don't want to run out of control methods for limiting weeds in farmers' fields," Snow said.
Oregon-based scientist Kelly Donegan, a researcher for the U.S. Environmental Protection Agency, summarized findings suggesting that genetically engineered crops cause unanticipated changes in soils in which they are grown, as transgenic plant products persist in the soil more than two months.
At an international meeting in January, Altieri noted, 130 countries, including the United States, signed an agreement endorsing the precautionary principle, which says that even though the evidence is not yet conclusive, it's better to err on the side of caution when introducing new technology like genetic engineering. The agreement allows countries to reject imports of genetically modified foods if they have a scientific basis for uncertainty as to their safety.
U.S. Senator Barbara Boxer and state Senator Tom Hayden, (D-Los Angeles), asked scientists attending last week's symposium to endorse a proposed bill requiring labeling of genetically modified foods. Most of the participants plann to sign on, Altieri said, as they believe consumers have the right to know what they are eating. A long list of scientists have endorsed a rival proposal, sponsored by U.S. Senator Christopher Bond, (R-Missouri), calling the labeling unnecessary.
Symposium participants agreed "that there are better and more sound agroecological alternatives to raise crops," said Altieri. "Ecologists are being distracted from the key work of developing agroecological alternatives by having to monitor the mess that a rushed-to-market technology is causing."